3.0T动态增强磁共振灌注成像对小肝癌射频消融疗效评估的价值研究

The application of 3.0T DCE-MRI in evaluating curative effect of radiofrequency ablation for small hepatocellular carcinoma:a clinical study

目的探讨动态增强磁共振灌注成像(DCE-MRI)定量评估小肝癌射频消融(RFA)疗效的预测价值。方法选取2016年3月至2020年6月初诊单发小肝癌病灶58例。采用Philips 3.0T MR对全部入组患者于治疗前行MR常规T1WI、T2WI、DCE-MRI序列扫描,分别测得肿瘤最大层面的各扫描序列定量参数-包括血管通透性常数(transfer constant,Ktrans)、血管外细胞外间隙容积百分比(volume of extravascular extraeellular space per unit volume of tissue,Ve)及血液回流常数(the rate constant,Kep)值。病理切片通过免疫组织化学方法检测微血管密度。根据mRECIST标准进行随访,将病例分为稳定组和进展组。比较两组RFA治疗前各定量指标的差异,计量资料组间比较采用独立样本t检验。用Pearson相关检验分析两组患者DCE-MRI各灌注参数与微血管密度(MVD)之间的相关性。结果稳定组以及进展组初始病灶大小差异有统计学意义,稳定组较进展组的病灶更小。消融前稳定组Ktrans值(0.343±0.074)min^(-1)、Kep值(0.904±0.153)min^(-1)及MVD值(49.000±5.518)均较进展组低,且差异具有统计学意义。两组患者治疗前DCE-MRI各参数值与MVD的相关分析显示Ktrans值、Ve值与MVD呈正相关,相关系数分别为0.677、0.334。结论动态增强DCE-MRI灌注分析参数Ktrans、Kep均能有效预测肝癌RFA疗效,且在一定程度上可对肿瘤的微血管密度进行检测。

Objective To discuss the predictive value of dynamic contrast-enhanced perfusion magnetic resonance imaging(DCE-MRI)in quantitatively evaluating the curative effect of radiofrequency ablation(RFA)in treating small hepatocellular carcinoma(SHCC).Methods A total of 58 patients with SHCC,who were admitted to authors’hospital between March 2016 and June 2020,were enrolled in this study.In all patients the diagnosis met the clinical diagnostic criteria of《Standard of Diagnosis and Treatment of Primary Liver Cancer》and was pathologically proved by puncture biopsy.Philips 3.0T MR scanner was used to perform preoperative MR routine T1WI/T2WI and DCE-MRI sequences in all patients,on the imaging section displaying the largest diameter of the tumor,the quantitative parameter values of each scanning sequence,including transfer constant(Ktrans),volume of extravascular extracellular space per unit volume of tissue(Ve)and the rate constant(Kep),were separately measured.Immunohistochemical method was used to detect the microvessel density(MVD)in pathological slice.Based on modified response evaluation criteria in solid tumor(mRECIST),the patients were divided into stable group(CR+PR+SD)and progressive group(PD).The differences in pre-RFA quantitative indicators were compared between the two groups.Chi-square test was used to compare the enumeration data between the two groups.The independent sample t-test was used to compare the measurement data between the two groups.By using Pearson correlation testing the correlations between each DCE-MRI perfusion parameter and MVD value were analyzed.Results There was a statistically significant difference in the initial lesion size between the stable group and the progressive group,and the lesion size in the stable group was smaller than that in the progressive group.In the stable group the pre-RFA Ktrans value,Kep value and MVD value were(0.343±0.074)min^(-1),(0.904±0.153)min^(-1)and(49.000±5.518)respectively,which were lower than those in the progressive group,and the differences between the two groups were statistically significant.The correlation analysis between each DCE-MRI perfusion parameter and MVD value indicated that the values of Ktrans and Ve were positively correlated with MVD,and the correlation coefficients were 0.677 and 0.334 respectively.Conclusion Both Ktrans and Kep of DCE-MRI perfusion analysis parameters can effectively predict the efficacy of RFA for liver cancer,and to some extent they can replace the histological examination of non-invasive detection of tumor MVD.